Addiator: Short introduction about a calculator from the 60s

[jedishrfu]

Yes, that's the one I had too.

 

[anorlunda]

3D printed Curta:
http://wudev.digitaltorque.com/2015/04/3d-printing-challenge.html?m=1

Outstanding! Thank you @YoungPhysicist.

 

[phinds]

Good grief Charlie Brown, I forgot all about those things over 50 years ago after learning how to use a slide rule but now I remember using one in high school.

 

[ali PMPAINT]

Lol, I didn't even know the existence of these calculators (I was born 2003), I can't imagine doing mathematics without digital calculators or computers. I heard that Leibniz and Pascal have made the first calculators, how theirs looked like?

 

[anorlunda]

Lol, I didn't even know the existence of these calculators (I was born 2003), I can't imagine doing mathematics without digital calculators or computers. I heard that Leibniz and Pascal have made the first calculators, how theirs looked like?

LOL on you. Many of us old timers here grew up in the slide rule era. Using a slide rule required the extra mental skill of keeping track of the decimal point in your head. That meant making a mental estimate alongside each calculation. That benefit disappeared when the slide rule died.

 

[YoungPhysicist]

That benefit disappeared when the slide rule died.

The slide rule never dies if someone is still talking about it. 😄

 

[berkeman]

Using a slide rule required the extra mental skill of keeping track of the decimal point in your head. That meant making a mental estimate alongside each calculation. That benefit disappeared when the slide rule died.

Some of us still do the calculation in our head first, and then check it with a calculator...

https://www.amazon.com/s?k=rapid+ma...aps,193&ref=nb_sb_ss_i_1_11&tag=pfamazon01-20

 

[phinds]

Some of us still do the calculation in our head first, and then check it with a calculator...

Yeah, sigh ... I USED to do that but my computing ability is not what it used to be. Of course it never really was what it used to be.

 

[ali PMPAINT]

So wait, how did you calculate trancsendental functions such sin(x), e^x, 2^x, in(x), etc? I mean, you wouldn't use a taylor series for each, would you?

 

[dlgoff]

So wait, how did you calculate trancsendental functions such sin(x), e^x, 2^x, in(x), etc? I mean, you wouldn't use a taylor series for each, would you?

From Wikipedia:

In addition to the logarithmic scales, some slide rules have other mathematical functions encoded on other auxiliary scales. The most popular are trigonometric, usually sine and tangent, common logarithm (log10) (for taking the log of a value on a multiplier scale), natural logarithm (ln) and exponential (ex) scales.

 

[cobalt124]

LOL on you. Many of us old timers here grew up in the slide rule era...

Maybe I'm slightly less of an old timer than others here, I was given a slide rule as a child but never learned how to use it. However...

Some of us still do the calculation in our head first, and then check it with a calculator..

I always do this as I am enough of an old timer to realize I'm not as sharp as I used to be and exercise it when I can to slow down the loss of mental ability.

 

[YoungPhysicist]

Some of us still do the calculation in our head first, and then check it with a calculator...

That skill is a must-have in my elementary school. You can't finish math tests in timethus can't graduate if you can't multiply two 4 digit numbers in 3 seconds. Not sure what it is like in US.

ps: No time for checking with calculators.

 

[fresh_42]

So wait, how did you calculate trancsendental functions such sin(x), e^x, 2^x, in(x), etc? I mean, you wouldn't use a taylor series for each, would you?

No problem. I have more scales on mine than I can understand their labels. Of course you have to know elementary mathematics first! E.g. there is no difference between $e^x$ and $2^x$.

 

[Klystron]

Good point about transcendental functions and computing in one's head. Take trig. Sure I learned the 'basic' and hyperbolic functions; but, for whatever reason, preferred using sine functions given the choice.

Consistently using sines (usually sinh) became a running joke back in the day on electronic warfare ranges. Everybody else used cosine formulas to convert various data into antenna pointing position. I would spend an extra second or two converting to sines providing some height information at the expense of azimuth precision. Worked well for me but was difficult to teach to others.

I once gave an on-site lecture to visitors going on about "converting map coordinates into target position angles then calculating sine...", entire crew shouts "Cosine!". Big laugh...

At the end of the talk a visiting NCO said they learned a lot but did not like all the religion.
"Religion?", I asked, incredulous.
"Yeah, you kept going on about Signs! Signs in the Sky! You sound like a preacher!".

 

[anorlunda]

Who remembers nomograms? One of my professors insisted that we all learned how to build our own nomograms to fit any situation. It was a curious skill. The only time I ever used it was when I was a firefighter.

Source: https://commons.wikimedia.org/w/index.php?title=User:Rrrddd&action=edit&redlink=1

 

[gmax137]

Nomograms were a favorite of engineers, see for example the Crane 410 fluid flow book. Fast, and as accurate as necessary / appropriate.

I have a little booklet, "how to construct nomograms," picked up used somewhere. I have to admit never actually making any.

 

[ali PMPAINT]

That skill is a must-have in my elementary school. You can't finish math tests in timethus can't graduate if you can't multiply two 4 digit numbers in 3 seconds. Not sure what it is like in US.

ps: No time for checking with calculators.

What?! In my country(maybe just my city), some high school students don't even know how to multiply two numbers by hand(They are very bad at mathematics), but they pass anyway...

 

[YoungPhysicist]

What?! In my country(maybe just my city), some high school students don't even know how to multiply two numbers by hand(They are very bad at mathematics), but they pass anyway...

That’s the case for Taiwanese elementary schools besides the one I go to.

There were also independent soroban classes in my elementary school. The problems are even harder(8digits divided by 5 dits in 4 secs) because the teachers said we have a calculator, which is just as ridiculous as it sounds.

 

[ali PMPAINT]

That’s the case for Taiwanese elementary schools besides the one I go to.

There were also independent soroban classes in my elementary school. The problems are even harder(8digits divided by 5 dits in 4 secs) because the teachers said we have a calculator, which is just as ridiculous as it sounds.

What?! How do students pass anyway? Is there a technique which one can use, or should they practice so much so that they can do it? Do they take it seriously?(Our school doesn't take anything serious lol)

 

[Nik_2213]

My child-hood paper-skills of long multiplication and division have endured despite log tables, slide-rules, scientific calculators etc etc...
And, yes, I was taught to 'add up', per the idiom, as that let you check 'take-aways'...

I loved wrangling quadratic equations, either by clever factorisation, or invoking the 'minus b plus or minus the square root of...' formula.
Sadly, though I could literally taste the power and beauty of full-on calculus, I could not get past basic integrations and differentials. Sorta 'glass ceiling'. I did keep trying, attested by my collection of math books dated a decade or so apart...